A Rotary Phone As A Computer Peripheral

November 26, 2021 by Jenny List 5 Comments

It’s an age-old conundrum for anyone working with retro hardware: preserve its original condition or not? The answer depends so often on a complex mix of how rare, obsolete or unusable the device is in its original form , and what the intended use for the device will be. For [Typhon Mind] who needed a novelty method of recording best wishes at a wedding through an old dial phone there was no need for it to be entirely original, so the solution was to turn it into a USB device for a host computer.

Out went the original circuitry, and in came a USB hub, a USB audio interface, and an Arduino. The original earpiece would suffice, but the microphone was replaced with a more modern one. The Arduino will register the cradle switch, and also power a set of LED addressable lights under the unit.

The result is a phone that retains all its looks, but has a new life as a PC peripheral. We’d venture to suggest that also using the Arduino to read the dial and produce DTMF tones might make it a valid peripheral for a VOIP application and complete the transformation, but that’s something that could be done at a later date. Maybe it could even be given a GSM makeover.

The Pros And Cons Of A Power Flush Toilet

November 20, 2021 by Lewin Day 36 Comments

By and large, toilet design hasn’t radically changed in a good long time. The problem was considered solved, and society moved on. However, [Handy Geng] was tasked by a friend to build a toilet with an extra-powerful flush, so he went ahead and did just that.

The concept is simple; the water tank in the custom-built toilet can be charged with pressurized air from a compressor when an more powerful flush is needed. Then, when the lever is pulled on that flush, the water will blast into the bowl with significantly more ferocity than usual.

[Handy Geng] also notes a further benefit from the system. By bolting down the toilet lid, using a gasket to seal it to the toilet bowl, the air pressure system can be used to blast out blockages and clogs.

However, there are some drawbacks. The toilet is nearly entirely constructed out of steel, a material that generally isn’t the first choice when working with water or bodily fluids. Additionally, the power flush mode tends to end up with water spraying out of the bowl due to the intensity of the spray.

Regardless, it goes to show that the toilet design is still an active area of research, and that we needn’t settle for the toilets we have today. More powerful, more capable models are just around the corner if we want them. Video after the break.

Continue reading “The Pros And Cons Of A Power Flush Toilet” →

Arduino Library Makes Digital Rain Like It’s 1999

November 17, 2021 by Tom Nardi 31 Comments

There’s going to be a new Matrix movie in theaters next month, and you know what that means: we’re about to see a whole new generation get obsessed with the franchise’s iconic “Digital Rain” effect. Thanks to modern advertisement technology, expect to see lines of glittering text pouring down the displays of everything from billboards to gas pumps pretty soon.

For those of us who’ve just been looking for an excuse to break out the old Matrix screensavers, you might as well get a jump on things using this handy Arduino library for the ESP8266 and ESP32. Developed by [Eric Nam], it lets you start up a digital rainstorm on displays supported by the TFT_eSPI library as easily as running digitalRainAnim.loop().

You can even install the library through the Arduino IDE, just open the Library Manager and search for “Digital Rain” to get started. You’ve still got to hook the display up to your microcontroller, but come on, [Eric] can’t do it all for you.

Looking at the examples, it seems like various aspects of the animation like color and speed can be configured by initializing the library with different values. Unfortunately we’re not seeing much in the way of documentation for this project, but by comparing the different examples, you should be able to get the high points.

While our first choice would certainly be a wall of green alphanumeric LED displays, we can’t help but be impressed with how easy this project makes it to spin up your own little slice of the Matrix on the workbench.

Continue reading “Arduino Library Makes Digital Rain Like It’s 1999” →

Treasure Hunting With A Handful Of Common Components

November 15, 2021 by Adam Zeloof 16 Comments

Sometimes simpler is better — when you don’t need the the computational power of an onboard microcontroller, it’s often best to rely on a simple circuit to get the job done. With cheap Raspberry Pis and ESP32s all over the place, it can be easy to forget that many simpler projects can be completed without a single line of code (and with the ongoing chip shortage, it may be more important now than ever to remember that).

[mircemk] had the right idea when he built his simple induction-balance metal detector. It uses a couple of 555 timers, transistors, and passives to sense the presence of metallic objects via a coil of wire. He was able to detect a coin up to 15 cm away, and larger objects at 60cm — not bad for a pile of components you probably have in your bench’s spare parts drawer right now! The detector selectivity can be tuned by a couple of potentiometers, and in true metal detector fashion, it has a buzzer to loudly blare at you once it’s found something (along with a LED, in case the buzzer gets too annoying).

All in all, this metal detector looks like a terribly fun project — one perfectly suited to beginners and more seasoned hackers alike. It serves as a great reminder that not every project needs WiFi or an OLED display to be useful, but don’t let that stop you from overdoing things! If touchscreens are more your speed, [mircemk] has got you covered with a smartphone-integrated version as well.

Continue reading “Treasure Hunting With A Handful Of Common Components” →

Those Bullet Effects In Terminator 2 Weren’t CGI

November 14, 2021 by Donald Papp 25 Comments

Remember Terminator 2? Guns were nearly useless against the murderous T-1000, played by Robert Patrick. Bullets fired at the “liquid metal” robot resulted only in a chrome-looking bullet splash that momentarily staggered the killing machine. The effects were done by Stan Winston, who died in 2008, but a video and short blurb shared by the Stan Winston School of Character Arts revealed, to our surprise and delight, that the bullet impact effects were not CGI.

How was this accomplished? First of all, Winston and his team researched the correct “look” for the splash impacts by firing projectiles into mud and painstakingly working to duplicate the resulting shapes. These realistic-looking crater sculpts were then cast in some mixture of foam rubber, and given a chromed look by way of vacuum metallizing (also known as vacuum deposition) which is a way of depositing a thin layer of metal onto a surface. Vacuum deposition is similar to electroplating, but the process does not require the object being coated to have a conductive surface.

These foam rubber splash patterns — which look like metal but aren’t — were deployed using a simple mechanical system. A variety of splashes in different sizes get individually compressed into receptacles in a fiberglass chest plate. Covering each is a kind of trapdoor, each held closed by a single pin on a cable.

To trigger a bullet impact effect, a wireless remote control pulls a cable, which pulls its attached pin, and the compressed splash pattern blossoms forth in an instant, bursting through pre-scored fabric in the process. Sadly there are no photos of the device itself, but you can see it in action in the testing video shared by the Stan Winston School, embedded below.

Continue reading “Those Bullet Effects In Terminator 2 Weren’t CGI” →

Chipboard prototype of a wireless phone charger with style.

Prototyping Your Way To Better Prototypes

November 13, 2021 by Kristina Panos 13 Comments

If you’ve ever made a prototype of something before making the “real” one or even the final prototype, you probably already know that hands-on design time can’t be beat. There’s really no substitute for the insight you will glean from having a three-dimensional thing to hold and turn over in your hands for a full assessment. Sometimes you need to prototype an object more than once before investing time, money, and materials into making the final prototype for presentation.

This is [Eric Strebel]’s second video in series about making an eco-friendly wireless phone charger. He made a paper prototype in the first video, and in this follow-up, he refines the idea further and makes a chipboard version of the charger before the final molded paper pulp prototype. The main advantage of the chipboard version is to design the parts so that each one will be easier to pull from its mold in a single piece without any undercuts.

By building the chipboard version first, [Eric] is able to better understand the manufacturing and assembly needs of this particular widget. This way, he can work out the kinks before spending a bunch of time in CAD to create a 3D-printed mold and making the paper pulp prototype itself. He emphasizes that this process is quite different from the 2.5D method of laser-cutting a single piece of chipboard and folding it up into a 3D object like it was a cereal box, which is likely to hide design issues. Be sure to check out the video after the break.

We think this prototype is quite nice-looking, and believe that everything deserves good design. Why should a wireless charger be any different? [Eric] has prototyped in a lot of media, but he seems especially skilled in the art of foam core board. Start with the masterclass and you’ll have a better appreciation for his foam armored vehicle and one of the many ways he smooths out foam parts.

Continue reading “Prototyping Your Way To Better Prototypes” →

Automated Air Cannon Shoots Smoke Rings

November 12, 2021 by Lewin Day 13 Comments

Air cannons are fun, and became a part of mainstream culture with the popular Airzooka toy. Of course, cocking and firing the Airzooka gets tiring after a while, and they’re kind of a little small. This build from [1alembic] delivers on both those counts.

The result is a bigger air cannon that repeatedly fires all by itself. The cannon itself is built out of a trash can with the bottom cut out. It’s then fitted with a diaphragm made out of a heavy-duty trash bag covered in duct tape for added strength. Latex hose is then installed inside the trash can, attached to the diaphragm. Thus, the diaphragm can be pulled back, and when released, it’s pulled forward, creating a rush of air through the trash can which generates a vortex ring just like the smaller Airzooka.

The automation of the cannon is beautifully simple. A string is attached to the back of the diaphragm, and wrapped around a rod so it can be wound up. This allows a wiper motor to turn the rod via a set of gears, pulling the diaphragm back.

However, the drive gear on the wiper motor has half its teeth missing. The system is then set up so that once the diaphragm is pulled right back, the drive gear gets to the missing teeth, allowing the winder rod to spin back freely as the diaphragm shoots forward, firing the air cannon. The cycle then repeats as the drive gear re-engages the winding mechanism.

Paired with a smoke machine, the air cannon will whirr away, firing beautiful smoke rings at regular intervals until it’s switched off. It’s an elegant thing that we’d love to leave set up at a party to add some atmosphere. We’ve seen other air cannons built with some real fire-power, too. Video after the break.

Continue reading “Automated Air Cannon Shoots Smoke Rings” →